1. Technical Field
The present disclosure relates to semiconductor devices and more particularly, to a memory card for controlling the drivability of a data drive circuit in accordance with a host and a method of driving the same.
2. Discussion of the Related Art
Due to advancements in technology, portable electronic devices are being equipped with functions in addition to their primary purpose. For example, a mobile phone may be provided with a camcorder function of taking motion pictures and a camera function of taking still pictures in addition to its inherent telephonic function. Such electronic devices generally require a large capacity storage unit to smoothly process the additional functions.
Portable electronic devices often use NAND flash memories to satisfy their large storage requirements. A NAND flash memory is a kind of nonvolatile memory which is typically present on a separable card (hereinafter, referred to as ‘memory card’) which can be inserted into the corresponding portable electronic device. For example, many commercial cards, such as the Multimedia card (MMC), the Secure digital (SD) card, the Smartmedia card, and the Compact flash card, are used as data storage units for digital cameras, MP3 players, personal digital assistants (PDA), handheld personal computers, gaming machines, facsimile telegraphs, scanners, and printers (hereinafter, referred to as ‘hosts’).
A memory card is usually conditioned in various environments of operation in accordance with a variety of hosts. It is important to offer compatibility of interface between the memory card and the host. For example, the memory card and host need to agree on setup/hold times for transceiving data between the them. Conventionally, such agreements are accomplished by using a drive-point delaying method at an output terminal during the design of the memory card. But, this is a cumbersome process because test operations are carried out with hosts that are practically operable with the memory card. Further, as terminal resistance and capacitance on data transmission lines between the host and the memory card vary in accordance with the type of host, it becomes difficult to optimally control the data drivability of the memory card.
Therefore, a need exists for a memory card which can control its data drivability.